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Full-Text Articles in Engineering
Estimation Of Joint Moments During Turning Maneuvers In Alpine Skiing Using A Three Dimensional Musculoskeletal Skier Model And A Forward Dynamics Optimization Framework, Dieter Heinrich, Antonie J. Van Den Bogert, Werner Nachbauer
Estimation Of Joint Moments During Turning Maneuvers In Alpine Skiing Using A Three Dimensional Musculoskeletal Skier Model And A Forward Dynamics Optimization Framework, Dieter Heinrich, Antonie J. Van Den Bogert, Werner Nachbauer
Mechanical Engineering Faculty Publications
In alpine skiing, estimation of the joint moments acting onto the skier is essential to quantify the loading of the skier during turning maneuvers. In the present study, a novel forward dynamics optimization framework is presented to estimate the joint moments acting onto the skier incorporating a three dimensional musculoskeletal model (53 kinematic degrees of freedom, 94 muscles). Kinematic data of a professional skier performing a turning maneuver were captured and used as input data to the optimization framework. In the optimization framework, the musculoskeletal model of the skier was applied to track the experimental data of a skier and …
Investigation Of Extremum Seeking Control For Adaptive Exercise Machines, Brahm T. Powell
Investigation Of Extremum Seeking Control For Adaptive Exercise Machines, Brahm T. Powell
ETD Archive
Many muscle rehabilitation regimens are non-adaptive and recommended subjectively by physicians. While there are advantages to having the feedback of a qualified physician, utilizing real-time muscle performance feedback could be beneficial. An extremum seeking control design is proposed to fulfill the need for an automated, load-varying exercise machine that can optimize muscle performance.
Several steps are outlined to contribute to the realization of this goal. First, the extremum seeking control scheme is discussed. Second, the Hill muscle model will be described. Theoretical muscle effort extrema will be derived for selected optimization cases, namely maximizing average squared power by varying load …
Human-Like Rewards To Train A Reinforcement Learning Controller For Planar Arm Movement, Kathleen M. Jagodnik, Philip S. Thomas, Antonie J. Van Den Bogert, Michael S. Branicky, Robert F. Kirsch
Human-Like Rewards To Train A Reinforcement Learning Controller For Planar Arm Movement, Kathleen M. Jagodnik, Philip S. Thomas, Antonie J. Van Den Bogert, Michael S. Branicky, Robert F. Kirsch
Mechanical Engineering Faculty Publications
High-level spinal cord injury (SCI) in humans causes paralysis below the neck. Functional electrical stimulation (FES) technology applies electrical current to nerves and muscles to restore movement, and controllers for upper extremity FES neuroprostheses calculate stimulation patterns to produce desired arm movement. However, currently available FES controllers have yet to restore natural movements. Reinforcement learning (RL) is a reward-driven control technique; it can employ user-generated rewards, and human preferences can be used in training. To test this concept with FES, we conducted simulation experiments using computer-generated ``pseudohuman{''} rewards. Rewards with varying properties were used with an actor-critic RL controller for …
An Elaborate Data Set On Human Gait And The Effect Of Mechanical Perturbations, Jason K. Moore, Sandra K. Hnat, Antonie J. Van Den Bogert
An Elaborate Data Set On Human Gait And The Effect Of Mechanical Perturbations, Jason K. Moore, Sandra K. Hnat, Antonie J. Van Den Bogert
Mechanical Engineering Faculty Publications
Here we share a rich gait data set collected from fifteen subjects walking at three speeds on an instrumented treadmill. Each trial consists of 120 s of normal walking and 480 s of walking while being longitudinally perturbed during each stance phase with pseudo-random fluctuations in the speed of the treadmill belt. A total of approximately 1.5 h of normal walking (>5000 gait cycles) and 6 h of perturbed walking (>20,000 gait cycles) is included in the data set. We provide full body marker trajectories and ground reaction loads in addition to a presentation of processed data that …
A Robotic Neuro-Musculoskeletal Simulator For Spine Research, Robb W. Colbrunn
A Robotic Neuro-Musculoskeletal Simulator For Spine Research, Robb W. Colbrunn
ETD Archive
An influential conceptual framework advanced by Panjabi represents the living spine as a complex neuromusculoskeletal system whose biomechanical functioning is rather finely dependent upon the interactions among and between three principal subsystems: the passive musculoskeletal subsystem (osteoligamentous spine plus passive mechanical contributions of the muscles), the active musculoskeletal subsystem (muscles and tendons), and the neural and feedback subsystem (neural control centers and feedback elements such as mechanoreceptors located in the soft tissues) [1]. The interplay between subsystems readily encourages "thought experiments" of how pathologic changes in one subsystem might influence another--for example, prompting one to speculate how painful arthritic changes …
A Comparative Study On Fault Detection And Self-Reconfiguration, Ning Ge
A Comparative Study On Fault Detection And Self-Reconfiguration, Ning Ge
ETD Archive
Extended State Observer (ESO) and the Alpha-Beta-Gamma Tracker are introduced and compared. In comparison, the ESO is found to be more noise resistant. The extended state used for the estimation of the general system dynamics in real time makes it suitable for fault detection. Four control schemes are proposed for self-reconfiguration upon fault detection. These schemes are Active Disturbance Rejection Control, Tracker-based Feedback Control, Fuzzy Logic Control and Tracker-based PID Control. To compare their control performance, these schemes are applied to three different applications namely Active Engine Vibration Isolation System, Three-Tank Dynamic System and MEMS Gyroscope System. The advantages and …
Stirling Convertor Control For A Lunar Concept Rover, Gina Blaze
Stirling Convertor Control For A Lunar Concept Rover, Gina Blaze
ETD Archive
NASA Glenn Research Center is developing various circuits for a lunar concept rover powered by both a stirling convertor and lithium ion batteries. To begin, a survey of six analog, non-power factor correcting controllers was done for an Advanced Stirling Convertor (ASC) design one was selected to control the stirling convertor. Next, a constant power circuit and lithium ion battery charger was designed, built and tested based on simulation in PSpice. The constant power circuit enables the stirling convertor to maintain a constant power when additional power is required from the batteries